The criminal possibilities of the online world have primed a "fourth era" of organised crime that is having a major effect on all forms of illegal activity around the globe, an academic study from John Grieve Centre for Policing and Security at London Metropolitan University has said.

By the reckoning of Organised Crime in the Digital Age 80% of crime committed online is now connected to organised gangs, mostly staffed by young-to-middle aged technical types working in connected groups of up to a dozen people.

A quarter of these gangs are recent enough to have started in the last six months with many also dabbling in traditional crimes including human trafficking, prostitution, drugs and theft.

The earliest online crimes included pump-and-dump stock scams in the late 1990s, but the real jump came with the development of the mainstream Internet around the turn of the century. Organised crime quickly picked up on the potential for information theft and fraud, which was eventually industrialised with the arrival of botnets around 2006.

"Organised criminal activity has now moved from being an emerging aspect of cybercrime to become a central feature of the digital crime landscape," said Kenny McKenzie, head of law enforcement for BAE Systems Detica, which commissioned the study. "Our report shows that more and more criminal activities now rely upon the online world."

Digital crime was only the latest era of organised activity, having succeeded the globalised drugs trade that started in the 1970s, the growth of the black market after World War 2, and the US prohibition era gambling and alcohol racketeering of the 1920s, the study said.

Unexpectedly, the study doesn't offer much about the geographical origins of online cybercrime possibly because such judgements can be misleading.

A disproportionate amount of malicious software development happens in countries such as Russia and its former Soviet Bloc satellites and China but increasingly the criminals wielding these tools come from almost anywhere.

Despite the documented incursions of East European gangs into Western Europe, a country's online criminal culture will often reflect its offline criminality.

"To tackle the problem of digital crime and intervene successfully, we need to move away from traditional models and embrace this new information about how organised criminals operate in a digital context," said Professor John Grieve of the John Grieve Centre for Policing and Community Safety.

"The research found evidence of many cases where there has been real success in closing down digital criminal operations. Growth in the digital economy will inevitably cause an increase in organised digital crime, however this need not be seen as an insurmountable problem," said Grieve.

The academics reached their conclusions after analysing "7,000 documentary sources including public, private and 'grey documentation," resolving the demographic and organisational patterns they found. Where these information came from was not specified.